The invention relates to a new and improved hotseal jaws and cutoff knife assembly for processing thermoplastic film bag making material, and is more particularly concerned with attaining substantially accurate cutoff at the end seals of reclosable plastic zipper carried by the material.
In such assemblies, the jaws are equipped to seal bag side areas of the bag making material. One of the jaws has a groove and the other of the jaws has a knife which extends into the groove for separating the material into individual bags. Although the bag making material is maintained taut between the jaws while the cutoff knife functions, there has been a roughness at the zipper end seal cutoff with a tendency toward leakage through the end seals of the zipper, as well as undesirable protrusion of zipper roughness at the end seals liable to cause damage to other bags during storage and shipment.